Slashdot Mirror
Dead Salmon's "Brain Activity" Cautions fMRI Researchers
AthanasiusKircher sends in a Wired writeup on what should surely be a contender in the next Improbable Research competition: wiring a dead salmon into an fMRI machine and showing it pictures of humans designed to evoke various emotions. "When they got around to analyzing the voxel... data, the voxels representing the area where the salmon's tiny brain sat showed evidence of activity. In the fMRI scan, it looked like the dead salmon was actually thinking about the pictures it had been shown. ... The result is completely nuts — but that's actually exactly the point. [Neuroscientist Craig] Bennett... and his adviser, George Wolford, wrote up the work as a warning about the dangers of false positives in fMRI data. They wanted to call attention to ways the field could improve its statistical methods. ... Bennett notes: 'We could set our threshold [of significance] so high that we have no false positives, but we have no legitimate results.... We could also set it so low that we end up getting voxels in the fish's brain. It's the fine line that we walk.'" The research has been turned down by several publications, according to Wired, but a poster is available (PDF).
Wiring red herring's brain? Will it think too?
Are you sure this doesn't prove the existence of the soul???
And here I though I had exterminated the last of the zombie salmon.
Atlantic "salmon" isn't really salmon, it's more of a salt water trout.
Fuck, if the thing is dead anyway, why not throw a human brain in there and get way better results.
They're definitely on track for an igNobel prize. Using a red herring instead of the salmon would have made it a near certainty. A kipper would normally be the best choice, apart from the lack of a head/brain.
Those who can make you believe absurdities can make you commit atrocities. - Voltaire
This story makes me reconsider my zeal to see Terri Schiavo die. If she was indeed experiencing brain activity despite her handicap, surely she would be considered more alive than a dead salmon.
Our consciousness is all just a series of nerve impulses and chemical reactions. If Terri was experiencing these reactions and impulses, I hate to say it, but we may have killed a human being and not just a vegetable.
God bless you, Terri Schiavo.
The point of the experiment was not to prove the type of fish.
How long until we have undead salmon providing emotional therapy services for humans? Or is Dartmouth employing Aqua Man?
da w00t. mtfnpy?
Fish are capable of all sorts of feelings for humans.
[..] it looked like the dead salmon was actually thinking about the pictures it had been shown. ... The result is completely nuts -- [...] as a warning about the dangers of false positives [...]
Looks to me like the dark matter syndrome: "Our theories wrong? Our calculations off by an insane amount? Unpossible! That can never be. Nature must be lying!"
Has anyone even checked if a dead brain can still have flows of energy through its brain? I mean light patterns still reach the retinas, and can still trigger signals, depending on the state of the neurons there. How long was that salmon dead? I know that pigs can be frozen to be clinically dead for long times (90+ minutes), and still be revived without much damage.
I'd at least check if there are actual signals of current going trough the brain (with an OTHER (better) instrument, before dismissing it. Every unchecked assumption is a good chance for flaw in your study. You wouldn't want it to be dismissed by peer review, because of a faulty assumption.
Any sufficiently advanced intelligence is indistinguishable from stupidity.
... which you didn't fake yourself.
But seriously, it happens not only in medicine. It also happens in physics. [pdf]
The Tao of math: The numbers you can count are not the real numbers.
and wonders what goes through the salmon's mind whilst doing so.
ôó
No no he's not dead, he's, he's restin'! Remarkable fish, the salmon, idn'it, ay? Beautiful plumage!
Scientists like to make themselves sound smart and sophisticated but when it comes right down to it, scientists are a bunch of arrogant pricks who know nothing and simply want the rest of us blue collar folks to fund their insane "dead salmon" experiments with our hard earned tax dollars.
Whether it is evolution or global warming, scientists have been wrong about everything since they first started talking about the natural world. It is well past time that we go back to a REAL understanding of the world through our minds and our hearts, not through cold and dead measurement of useless facts.
Even vegetables put into an MRI machine for a functional scan can show some 'brain activity', simply because the fMRI doesn't actually show 'brain activity', it (in its typical configuration) shows blood oxygenation concentration levels in various places in the brain. The real problem is translating increasing or decreasing levels of oxygenation into brain activity. That's precisely what this study is showing: even a dead fish has changing brain-blood oxygenation levels. You need to remember to do the science and the math part of the problem, and make sure that the statistics are really showing meaningful relations.
The question remains as to what functionality is required to call a person "alive" or "brain dead". If you want to be as absolutely conservative as possible, anyone with a beating heart and working brain stem (corneal reflexes, heart-beat signal, breathing stimuli, etc) and can be considered alive, even if their entire frontal lobe has been entirely caved in removing any wisp of humanity and they aren't even capable of controlling their bowels or bladder or many other autonomic or homeostatic functions. Whether you think it's cruel to pull the plug on someone in this state is entirely up to personal beliefs and/or religious convictions. Medicine tries not to tread too deeply into this water, simply because it's not worth it to rehash the ethical dilemmas with no new science to change anyone's opinion. We leave it up to the individuals (through advanced directives, living wills, etc) and their families to choose.
Just don't be fooled into thinking that scattered activity in a bundle of nerves we happen to call a brain necessarily means she's "alive".
"Victory means exit strategy, and it's important for the President to explain to us what the exit strategy is." G.W.Bush
fMRI is a blunt instrument compared to what ultra high resolution spectroscopic MRI will show us in the future.
Current MRI is tuned to the proton nmr signal (and variations of it). As magnet technology advances and ginourmous gradients are achieved, it will be possible to obtain full spectroscopic data (chemical shift) in addition to positional data. Not only for the proton but for other isotopes that produce an NMR signal (of which all the CHONPS elements have at least one). As aquisition electronics speed increases it should eventually be possible to show this data in real time (molecules in motion). Of course it will be a trade-off between positional data resolution and spectroscopic data resolution, but this will be a very powerful technique. fMRI is just the tip of the iceberg and only a first step toward spectroscopic MRI proper.
That said (and without RTFA of course), I wonder how long the salmon was dead? What temperature was it stored at? The animal need not necessarily be alive for a stimulus to produce an effect. (Thinking of batteries and frog legs...) As long as the bulk of the cellular machinery is intact...
OK, I broke down and read the pdf. This report is coming from a psyhchology department! (I expected biology) I'd wait until the chemists and physicists weigh in to make any conclusions about this observation.
Posted by: lolcatz | 09/18/09 | 8:56 pm
Fridays must be slow news days at Wired
Posted by: xznofile | 09/18/09 | 9:24 pm
Some scientists are so blindered by convention that they canâ(TM)t recognize obvious potential when they see it, I mean who says culinary post-processing can only be done on fish?
Posted by: necro144 | 09/18/09 | 9:35 pm
this is true. Iâ(TM)d like to see the voxels of a truffle when exposed to a close up of a snout.
Step it up /.
Even Wired is one-upping you guys.
Looks to me like the dark matter syndrome: "Our theories wrong? Our calculations off by an insane amount? Unpossible! That can never be. Nature must be lying!"
I find it amazing that people who haven't even bothered to study the data or the reason for hypotheses like dark matter feel the need to make ass backwards comments about people who've literally dedicated their lives to it. What do you actually know about dark matter and the current state of the evidence? Do you even understand it at a layman's level let alone understand the insanely complex math? Have you heard of the bullet cluster? Do you know about the rotation curve of galaxies? Do you understand anything about the cosmic microwave background and its fluctuations? Do you understand the background theories you're ridiculing? Do you know why General Relativity fits the data we have collected so well? Have you even bothered to find out why scientists believe in these things? Dark matter and dark energy aren't just theories that a bunch of arrogant pricks pulled out of their asses. These are our best attempts to fit multiple kinds of data into a single theory of nature. Your attempt to imply it's just scientists refusing to believe the data is at best childish. At worst you're no better than a flat earther.
These posts express my own personal views, not those of my employer
Can we conclude from this data that the salmon is engaging in the perspective-taking task? Certainly not. What we can determine is that random noise in the EPI timeseries may yield spurious results if multiple comparisons are not controlled for. Adaptive methods for controlling the FDR and FWER are excellent options and are widely available in all major fMRI analysis packages. We argue that relying on standard statistical thresholds (p 8) is an ineffective control for multiple comparisons. We further argue that the vast majority of fMRI studies should be utilizing multiple comparisons correction as standard practice in the computation of their statistics.
And why wasn't this published? The very conclusion is that we should be more careful when trusting fMRI results and conduct more testing before jumping to conclusion.
I am the lawn!
We are not and will not be privy (at least for some time) to the reasons this research has been rejected by multiple peer-reviewed journals. Multiple rejections makes me as a researcher think that there are bigger problems then wording - I would lean heavily towards there being methodology flaws. I'd have to wonder (which I can't tell from the Wired article, a publication not known for its neurological expertise) some very basic questions that most everyone will be able to understand the importance of - why not multiple dead salmon, why no live salmon, and where is the discussion of any existing fish fMRI. I am not an expert in fMRI methodology or interpretation, but based on the friends I have that are, it's pretty complex. I'm not sure that this work makes a good argument towards the points this fellow is trying to hammer down.
Dead salmons swim on water. What else swims on water? Wood! Right. So dead salmons must be made out of wood. What else is made out of wood? Witches! Right. And witches can think! So the dead salmon must be thinking!
You're stupid.
Zombie Eaters...
So you're saying that this is dead research which someone put into Slashdot and it seemed to show signs of life under this extreme condition.
Atlantic salmon is called Salmo salar in biology-speak. It is the model species of the entire order Salmoniformes. Salmon doesn't get any truer than that. Pacific species belong to the genus Oncorhynchus. They are true salmons too. "Trouts" belong to both Oncorhynchus and Salmo (and another 5 genera). Some of these trouts have anadromous forms (that is, go to the seas and return to the rivers to spawn), for instance, the rainbow trout (called steelhead in its anadromous form) is Oncorhynchus mykiss and the brown trout (sea trout) is Salmo trutta.
Shouldn't be too much different than our current rulers, other than they will start to stink a little sooner...
Any insufficiently advanced magic is indistinguishable from technology.
Well, maybe what they saw wasn't a false positive? Maybe there is residual functionality of the brain some time after death, the same way you can electrically stimulate the muscles of a dead body to make them twitch. Is it that unthinkable that visual impulses have some effect on the brain, that death instantly renders every single braincell inoperable?
GAAH! MY PRINTER IS ON FIRE!!! PUT IT OUT! PUT IT OUT!
and add a -1 braindead option. this could solve 95% of all moderation issues
everything squared... it's either post nonsense or do dishes and cook brunch.
ideopath @ play
That fish that you are eating is watching you... and feeling it.
... if I understand the research correctly, it's suggesting that if I want a zombie army, salmon is the best place to start. And it will know when I'm pissed off from the look on my face.
I love how on slashdot, if you are not an acolyte in the "science is never wrong" religion, you are *ALWAYS* moderated down as a troll or as flamebait. Make all the intelligent, logical, and reasonable arguments you want, but if you hit too close to home, the censors of slashdot moderate you away. Too bad for you lot that ignoring the Truth will not make it go away.
The Deadites are watching.
Truly, this Salmon is causing a lot of Doubt.
...intelligent, logical, and reasonable arguments...
Uh...
Scientists like to make themselves sound smart and sophisticated but when it comes right down to it, scientists are a bunch of arrogant pricks who know nothing and simply want the rest of us blue collar folks to fund their insane "dead salmon" experiments with our hard earned tax dollars.
Very seriously, this is cool research! The really sad thing here is that they have trouble publishing. This shows that the interest in medical research is less on truth and knowledge and more on stunts and commercializable results.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Guess What ? It Never Ends...
Being in the Atlantic, after all.
Nonetheless, when selling salmon one downplays origin if Atlantic and advertises it if Pacific. Atlantic is a cheap substitute, like imitation crab.
The poster highlights a very well-known problem in statistics that folks doing brain research are well aware of and almost always correct for. The issue is that, when you're doing a large number of statistical tests, like you are with brain imaging data, you're likely to get a lot of false positives. You can correct for this by using a very conservative significance threshold (i.e., "p-value"), directly controlling for the proportion of false positives using a statistic called the "false discovery rate," controlling for false positives via monte carlo simulation, etc. etc.
Most neuroscientists who do brain imaging are very familiar with these correction methods, and apply them with great success. If anything, neuroscientists tend to be too concerned with false positives, such that they end up actually missing real activations because they're over-correcting.
So it's actually really unfortunate that this study is getting so much popular media attention, because it's giving people the impression that researchers aren't aware of this problem and/or that that they aren't doing anything about it. That couldn't be further from the truth.
The joke possibilities are endless but I won't bother. It's like shooting fish in a barrel.
I will be at the IgNobels next week, down in the floor seats. Can I stand up and nominate this research from the floor?
If Slashdot were chemistry it would look like this:Cadaverine
I for one welcome our necrotic scaly nuclear-resonant anadromous overlords.
Hey guys - I am the first author of the Salmon poster. If you have any questions that you would like us to answer then post it as a reply below and I will do my best to respond as soon as I can.
You can find some more information on the poster at the following link:
http://prefrontal.org/blog/2009/06/atlantic-salmon-index/
Best ~ Craig Bennett
But if I want salmon or crab, that's not what I mean.
I, for one, welcome our dead, picture viewing, active brain having Ichthyoid Overlords.
Dead fish tell no tales.
This is a good example of why one should never use a predefined threshold for significance when measuring a notoriously poorly calibrated and wildly variable biological characteristic.
I'd rather measure the airspeed velocity of an unladen swallow (any kind) :).
Unless they plan on using a fMRI as a means of determining if something is deceased, I fail to see the problem with it. The actual signals would probably override any kind of intrinsic result for the control tests.
And now let us have a bunch of jokes about how we shouldn't leap to conclusions, and the downstream speed of their internet is much better than the upstream.
This is great stuff. Hook that dead fish to a polygraph and have Penn and Teller go over the results.
--
Toro
I've watched dead people produce the occasional "heartbeat" on a monitor, even hours after being pronounced dead. It's called "pulseless electrical activity", and it doesn't mean anything except that obviously not all the cells in your body die at once.
Some of them try to continue to function, expending their last ATP reserves as their membranes become permeable and they start to flood with previously stored calcium.
Just because "brain death" occurs at roughly 4 minutes after circulation/oxygen supply is interrupted in humans does not necessarily mean that every single neuron dies at the same time. Simply the brain ceases to function as intended, and individual surviving neurons die depending on how stocked they were with ATP initially, what the microenvironment around them was like, etc. However (with few exceptions, ie people submerged in nearly freezing water), enough neurons die at 4 minutes to cause an irreversible damage to the brain that is incompatible with life.
I can only talk about humans, because that is my specialty. However I don't think anything with a brain can be much different. All vertebrates are generally similar when you disregard the specific biochemical or physiological adaptations for specific environments.
For those wanting to believe this as some sort of "evidence" of "life after death", ask the researchers if they got the same reaction from these fish when they had been dead for a few weeks... I don't know about fish, but human brains generally liquefy after about 24 hours... yes that's right, they turn to mush.
Seven puppies were harmed during the making of this post.
After all, the dead salmon had a part time job as a journalistic quality editor for FOX.
The sole has no eyes.
So many...ellipses in summary...make it hard to...believe....like...telegram from distant...planet
"Some circumstantial evidence is very strong, as when you find a trout in the milk."
-Henry David Thoreau
The Admin and the Engineer
and showing it pictures of humans designed to evoke various emotions.
What kind of emotions do fish have for humans except fear?
Assuming the fish was thawed, couldn't the electrical field of the fMRI induced neuronal activity?
We further argue that the vast majority of fMRI studies should be utilizing multiple comparisons correction as standard practice in the computation of their statistics.
Gee, I dunno...
Key question: when does electrical activity stop being meaningful? Even when a body falls apart I would imagine there will be measurable effects, but more of a galvanic origin.
Insert
The need for multiple comparison corrections is standard knowledge among cognitive neuroscientists. It is actually common practice for manufacturers of MRI machines to image inanimate objects as a test of the machine. You could easily get that data, rather than imaging a dead fish. Once you know the amount of noise, it would be easier to just simulate within a statistical program to determine the effects of not correcting. If the authors of the poster weren't aware of the value of multiple comparison corrections BEFORE they stuck a fish in the magnet, at least they learned a lesson everyone else gets in second year stat.
I do fMRI research, and I can tell you that this poster does not constitute a successful critique of modern fMRI methods.
The result reported here is only significant when not properly accounting for multiple comparisons or spatial extent. When the authors do use an appropriate method (such as False Discovery Rate), the poster reports that no voxels survive thresholding. In the vast majority of circumstances no one accepts a 3-voxel "activation" in fMRI precisely because they are likely to happen by chance alone.
The paper says: Identical t-contrasts controlling the false discovery rate (FDR) and familywise error rate (FWER) were completed. These contrasts indicated no active voxels, even at relaxed statistical thresholds (p = 0.25).
Basically, this shows that when you do your thresholding wrong, you get meaningless results. Nothing to see here.
All those fish looking at me at the fish market is going to give me the shivers now...
This is only one small example to why the guys running around randomly plugging in wires will not get AI. There is a whole lot more to it, than simply getting that square plug to fit in the right round hole.
Living in Chile
They say you're brain is active after death for about 40 days (electrical signals). This is what I believe is heaven/hell for people and then we slowly fade as an individual and become one with the universe.
I just finished watching the second season premiere episode of Fringe. This sounds completely plausible. In fact, I'm surprised they didn't expect this result.
How is this notable, again?
And I, for one, welcome our new undead zombie salmon overlords!!
Fixed that for you.
The fact that you are unable to put up a reasonable counter argument to my claim that scientists are largely useless, always arrogant and consistently waste a LOT of taxpayer money on projects that make little sense only goes to further my point. The fact that you were moderated UP for such behavior also shows what kind of a narrow minded, Aristotelean philosophy rules this place.
Here come the "troll" / "flamebait" censors now.
what would the readings be if they hooked up my PHB and scanned his "brain" ...
Just sayin'
The contest for ages has been to rescue liberty from the grasp of executive power. -- Daniel Webster
Right? "Only dead salmon go with the flow" - however, undead salmon continue to have feelings . . . hmmm. Good Job Sarah Salmoncuda!
"You never want a serious crisis to go to waste." - Rahm Emanuel
Do Dead Salmon Dream of Electric Sheep? According to this device, they do!
ardeaem - At face value you are absolutely right. The majority of cognitive neuroscientists do use multiple comparisons correction in their research. Our commentary is targeted at the remainder of researchers who continue to use uncorrected statistics. The percentage is larger than you might believe, and my co-authors and I are of the opinion that we need to get our statistical house in order for the field to mature.
I recommend some fava beans and a nice chianti to go with your salmon. Really balances out the taste. fuhfuhfuhfuh
I didn't RTFA, but was it those crazy Islamofascicts that finally got him?
.
- aqk
F U
How do you know the salmon was actually dead?
Did the wave collapse when the salmon's box was opened?
Oh. Sorry! Wrong experiment...
.
- aqk
F U
In the 1930's someone did careful research on how to study rats in mazes. Some things became clear: the rats could smell their prize from a long way, and would find it using their nose and not by being smart and having learned how to travel the maze. Similarly the rats have good hearing. They hear their feet tapping on the bottom of the maze, and these sound waves travel in a distinct way through the (usually wooden) bottom of the maze, bouncing off hidden prizes and thus revealing their location.
The researchers warned about the many different ways that research on rats running through mazes could go wrong. But they didn't have any actual rats-running-through-mazes results. So their research got mostly ignored. And others continued to be amazed at the smarts of the rats while the rats happily smelled their ways to the prizes.....
Now, for the question of what to do when editors let manuscripts through with uncorrected p-values: I say, we invite them all to a conference, along with all researchers who accept the null hypothesis based on p>.05, and those who think that p is the probability of the null being true. Then, we laugh at them. Maybe they'll get the point. (Can you tell I'm a bitter methodologist? :)